Spectrum Controls 1769sc-IF8u - Manual (Page 23)

Chapter 2: Quick Start for Experienced Users 13
• To ensures optimum accuracy, limit overall cable impedance by
keeping a cable as short as possible. Locate the module as close to
input devices as the application permits.
Grounding
!
ATTENTION! The possibility exists that a grounded or exposed
thermocouple can become shorted to a potential greater than that of the
thermocouple itself. Due to possible shock hazard, take care when wiring
grounded or exposed thermocouples. See Appendix D, Using Thermocouple
Junctions.
• This product is intended to be mounted to a well-grounded mounting
surface such as a metal panel. Additional grounding connections from
the module’s mounting tabs or DIN rail (if used) are not required
unless the mounting surface cannot be grounded.
• Keep cable shield connections to ground as short as possible.
• Ground the shield drain wire at one end only. The preferred location is
as follows.
- For grounded thermocouples or millivolt sensors, this is at the sensor
end.
- For RTD and resistance sensors, this is at the module end.
- For insulated/ungrounded thermocouples, this is at the module end.
Contact your sensor manufacturer for additional details.
• Refer to Industrial Automation Wiring and Grounding Guidelines,
Allen-Bradley publication 1770-4.1, for additional information.
The terminal connections for the CJC sensor are shown below: